Re: How getmail deals with delivery errors and with bounce e-mails

On Wed, 2020-11-04 at 20:49 +0100, Langenxx Feld wrote:
> Let's look at this again, because I haven't quite understood that yet.
> 
> When getmail fetches a message via POP3, and trying to deliver it
> fails:
> 
> 1) getmail leaves the message in the POP3 mailbox, so next time around
> it will be retried.
> 
> 2) getmail prints an error to stderr, but does not stop, it just
> carries on with the next mail.
> 
Correct.

> getmail does not document an exit code, which can be consider an
> oversight (a software quality defect) in itself.
> 
Of course. Its not a fatal error. 

If getmail finds a message it can't deliver, it emits a message saying
what happened and continues until it has processed all the messages in
the mailbox, at which time it has:
- delivered all the message that were deliverable
- delivered warnings about any messages it could not deliver

It has done what it was designed to do, so it emits a zero exit code and
shuts down normally.
 
> So getmail will not tell you that one of the e-mails has failed to
> deliver.
> 
Wrong. It can and does notify you about undeliverables. Its then up to
the sysadmin to investigate and fix whatever made the message
undeliverable. Thats why its still sitting in the ISP's mailbox.

> If you are using an internal Postfix, you are actually going the way [
> external provider MDA -> POP3 -> internal MTA ].
>
Postfix does what its configured to do which can include dealing with
nonexistent local users without bouncing them. See, among other items,
the luser_relay parameter in main.cf


Martin